Methods for the uniform functionalization of polyethylene surfaces are being developed, with the intent of providing polymeric materials having properties compatible with biomedical engineering applications. A series of procedures are being developed to analyze for surface functionality, and chimistry for modification of these surfaces is being explored. The chemistry of oriented multilayer fatty acid films is being explored, with particular emphasis on the influence of extent of orientation on the permeability of these films to small molecules. Synthetic approaches to new fatty acit derivatives, and to large ring carbocyclic molecules to be used as "carriers" in passive membrane transport experiments are being explored.